Thunderbird is a total redesign of the
Mozilla mail component to produce a
cross-platform, stand-alone mail application using
the XUL user interface language. It has many new
features, among them the ability to customize
your toolbars the way you want them. a new look
and feel with a large number of downloadable
themes which alter the appearance of the client,
and the ability to add UI extensions.

Atmail is a fully-featured email server and Webmail client, allowing users to send and receive email via a Web browser or mobile device. It has full support for
IMAP mailboxes, and an optional email-server mode that uses EXIM as the MTA. Features include a scheduler, MySQL backend support, spell-check, address book, calendar user preferences, multiple accounts, SpamAssassin support, migration scripts from other mail servers, a customizable interface, an attractive AJAX interface, an optional group sharing Calendar/Addressbook, and an Outlook plugin to sync Contacts/Tasks/Calendar data between a Desktop, Mobile, and Webmail client or other email users.

Cyphertite is a tar-like secure remote archiver. It deduplicates, compresses, and encrypts data prior to transmission, providing total privacy while reducing unnecessary wire traffic. It seamlessly supports IPv6 and IPv4 on a variety of platforms.

DOLPHIN SMASH is a mixed-signal, multi-language simulator for IC or PCB designs. It uses SPICE syntax for analog descriptions, Verilog-HDL and VHDL for digital, Verilog-A/AMS, VHDL-AMS and ABCD (a combination of SPICE and C) for analog behavioral, and C for DSP algorithms.

KAlarm lets you schedule personal messages to display, audio files to play, commands to execute, or emails to send. Among its options, it allows you to choose the message font and color, recurrence schedule, whether to display an advance reminder, whether to speak the message or play a sound when it is displayed, and whether to cancel the alarm if it can't be triggered on time (e.g. if you are logged out at the time). As well as using the graphical interface to configure alarms, you can use the command line, and there is a D-Bus/DCOP interface for other applications.

MuseScore lets you notate and compose music easily with your keyboard, your mouse, or a MIDI keyboard. You can print beautifully engraved sheet music or export it as PDF or PNG. You can play your score, transpose it, and save it as audio or MIDI file. MuseScore also supports MusicXML to let you share your composition with other scorewriters. MuseScore is often advertised as a cost effective alternative for Sibelius and Finale.